Rotary pump



M. CRAWFORD.

ROTARY PUMP.

APPLICATION FILED JAN. 12. 1921.

Patented Aug. 22, 1922.

UNHTEED) STATES Parent oar-ice.

MIDDLETON CRAWFORD, OF SPOKANE, WASHINGTON, ASSIGNOR TO SPOKANE IRRI- GATION PUMP COMPANY, OF SPOKANE, WASHINGTON, A CORPORATION OF WASH- INGTON.

ROTARY PUMP.

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Application filed January 12, 1921.

To all whom it may concern Be it known that I, lVIIDDLETON CRAWFORD, a citizen of the United States of America, residing at E. 2413 Third Avenue, Spokane, Spokane County, State of lVashington, have invented new and useful Improvements in Rotary Pumps, of which the following is a specification.

This invention relates to rotary pumps wherein rotary drums are arranged within a casing, one being provided with vanes for carrying the fluid from the inlet to the outlet side of the casing and the other acting as a rotary abutment drum and being provided with recesses adapted to be engaged by the vanes on the other drum as they pass from the outlet to the inlet side.

The main object of the present invention is to provide a pump, which for its weight and simplicity in construction, is adapted to pass a comparatively large quantity and a continuous flow of fluid.

The object of the invention is furthered particularly by means of'the special construction as to the form of the vanes in the one drum and the recesses in the other, whereby the fluid is prevented from pocketing in the recesses and being turned back to the inlet side of the casing.

It is recognized that a certain amount of liquid will reach the recesses in the drum and a. special object is to so construct the vanes and the recesses that the liquid reaching the recesses will be easily and rapidly expelled in the rotation of the drums without forcing the same through a stricture.

A still further object is to form the vanes so as to cause as little displacement of the liquid in the casing as possible.

The power to drive the pump is applied to the shaft of the drum carrying the vanes and the other drum is an idler, the two being connected by timing gears mounted preferably within the casing.

The details of construction will be hereinafter described, pointed out in the claim and illustrated in the accompanying drawings in which Figure 1 isa side elevation of the pump with one side of the casing removed, showing the vanes and recesses on the respective drums in certain relative positions.

Figure 2 is a like View showing such vanes and recesses in other relative positions and Specification of Letters Patent. Patented Aug, 22, 1922.,

Serial No. 436,732.

Figure is a vertical sectional view taken on the line 33 of Figure 2.

In a detail description in which. like nu-- mera-ls refer to like parts throughout the several views, a casing 10 is formed of parts 1l12 secured together as by bolts 13.

A shaft 14.- mounted in blind bearings 15 carries the recessed drum 16.

A shaft 17 mounted in a blind bearing 18 and in an open bearing 19 carried the vane drum 20.

The shaft 14: also carries a gear 21 and the shaft 17 a gear 22, the two inte-rmeshing and serving to time the rotation of the drums 16 and 20.

The shaft 17 extends outwardly through the open bearing 19 and to this shaft the power to operate the pump is applied.

Into the open bearing 19 is threaded a sleeve 23, serving to retain a suitable stuffing filled within the space 24 to prevent leakage from the interior of the casing 10 around the shaft 17.

Reference will now be made to the particular construction of the drum 16 as pertains to its recessed portions and to the drum 20 as to the particular construction of its vanes.

When the two drums are of different diameters, as is the case in the illustration shown in the drawings, they have a combined rolling and sliding contact as also do the vanes in the one and the walls of the recesses in the other.

The walls 25 and 25 of the recesses 26 of the drum 16, are separated by a substantial U-shaped portion 27 at the bottom of the re cess 26 and beyond that have substantial crescent-shaped walls, substantially paralleling each other.

The vanes 28 of the drum 20 are substantially-crescent shaped with a narrow body, to cut down the liquid displacement.

The ends 29 of the vanes 28 are shaped to conform to the wall of the casing 10 and to the walls of the recess 26.

The drums are timed in their rotation so that when an engagement of the vanes and recesses takes place, as the peripheries of the drums separate a contact is formed at the point 29 on the vanes, with a point 30 on the wall 25 of the recess 26.

The contact between the vanes 28 and the walls of the recesses 26 continue as the rota tion of the drums proceed and such contact is not broken until the walls of the two drums 16 and 20 come in contact with each other.

The drums rotate in the direction of the arrows and owing to the shape of the walls of the recess 26 and'the shape of the vanes 28, a rapid separation of the walls of the drums 16 and 20 takes place at the point 31 and 32, so that the liquid content in the pocket 33 is freely expelled in the rapid rotation.

Inlet opening 34 and outlet opening 35 are provided in the casing 10.

Liquid will be drawn through the casing 10 in the direction of the arrows.

With the construction and operation of the vanes and recess as shown and described, there is little opportunity for the passage of liquid between the drums and what gathers in the recess is easily and freely expelled.

VVha-t is claimed is:

A rotary pump comprising a casing in which is mounted two rotary drums, one of which drums is provided with crescent shaped vanes and the other of which drums is provided with corresponding recesses adapted to engage said vanes in the rotation of the drums, the periphery of said drums having a rolling contact with each other, excepting asto the said vanes and recesses, the side walls of such recesses being substantially crescent shaped, substantially parallel with each other, one of such walls being convex and the other concave, the two walls being separated at their inner ends by a substantially U-shaped wall, the relative forms of the blades and-walls of the recesses being calculated to pass comparatively long blades through recesses having comparatively narrow openings, thereby comparatively increasing the peripheral rolling contact of the drums to increase the capacity of the pump.

In testimony whereof, I aflix any signature in the resence of two Witnesses.

IDDLETON CRAWFORD. Witnesses:

CHARLES A. ATEN, L. L. WESTFALL. 

